In 2001, on South Uist, an island in the Outer Hebrides off the western Scottish coast, archaeologists led by Mike Parker-Pearson of the University of Sheffield found two unusual skeletons beneath the floor of a 3,000-year-old house. It was one of four so-called “round houses” at Cladh Hallan, a site named for a nearby modern graveyard, on a strip of sandy ground populated from 2000 B.C. to A.D. 1300. One of the skeletons, apparently an older man, had died around 1500 B.C.; the other, a woman, around 1300 B.C. What place do skeletons buried in sandy soil have among all these leathery bog bodies? Analytical tests and careful observation revealed that the two bodies had been deliberately mummified in a bog—the only known mummies among the early tribes of Europe.

Parker-Pearson and his team came to this conclusion as they grappled with some confusing observations. Both skeletons were intact and buried in a tight fetal position. The woman had two of her teeth removed and placed in her hands after death. The man’s remains were even stranger—he had the torso and limbs of one man, the skull of another, and a jawbone from a third, and the three had died over a span of 150 years. By radiocarbon dating the remains and charred grain on the floor of the house, the researchers determined that the bones had been buried long after death, meaning they spent hundreds of years out of the ground. But the skeletons were still articulated, indicating that skin and sinew were holding them together when they were buried—something not possible in the damp climate of South Uist without some form of artificial preservation.

The bones were the only clues the researchers had to unravel the tale. When a body decays, bacteria in the gut break down tissue and bore tiny holes in bone. Testing the density of the bones, the team determined that decomposition had begun, but then was suddenly halted. Also, they found that the outer layer of the bone had begun to demineralize, as it would in an acidic environment...like a bog. Careful measurement and analysis showed that the bodies had been intentionally preserved in a bog—even today, bogs can be found just a few miles away—for 6 to 18 months, or long enough to stop decomposition and tan skin and sinew, but not long enough to demineralize bone completely. The bodies were then removed from the bog, wrapped, and displayed in a warm, dry, and presumably sacred place for hundreds of years. The two individuals may have been rulers—not quite pharaohs, but leaders—or prominent people. This suggests ancestor worship was strong in prehistoric Europe, but leaves behind a number of mysteries, such as why one body was a composite and why they were eventually buried. “This raises more questions than it answers,” says Jacqui Mulville, a co-director of the project from Cardiff University. A testament to the preservative characteristics of the bog, the mummies of Cladh Hallan spent hundreds of years in a damp, windy climate much less hospitable to preservation than the Egyptian desert. “This practice may have been more common than we know,” says Mulville. “As a result of our work, existing material is being reexamined for further evidence of ‘mummification’ and preservation of human remains.”